going to show you how to use session in dot net core MVC application

Add below reference
using Microsoft.AspNetCore.Http;
using Newtonsoft.Json;

Settings to use Session in asp.net core -

Open startup.cs class

Add below line in ConfigureServices section

services.AddSession(options =>
{
    options.IdleTimeout = TimeSpan.FromMinutes(30);

});

Add below line in Configure section

app.UseSession();

Note - If you will not add these values then you will get below error

System.InvalidOperationException: 'Session has not been configured for this application or request.'

First Method

Set Value in session Variables
In Home Controller Index Method set Session Data As-

public IActionResult Index()
 {                       
     HttpContext.Session.SetString("UserInfostatic", "Shashi");           
     return View();
 }

Add another Controller And write below code to get session data

public IActionResult Index()
{
    var userInfostatic = (HttpContext.Session.GetString("UserInfostatic"));
    if(userInfostatic != null)
    {
        ViewBag.sessiondata = userInfostatic;
    }
return View();
}
 

Second Method

Set and Receive/Get session Data in Class Variable As -

Add class in Model  and set value in model class variable As-

public class UserInfoBO
    {        
        public int Id { get; set; }
        public string Email { get; set; }
        public string Cust_Name { get; set; }
        public string UserType { get; set; }

        public UserInfoBO LoadUserData()
        {
            var userdtl = 
                 new UserInfoBO()
                 {
                     Id = 1,
                     Email = "abc@gmail.com",
                     UserType = "Admin",                   
                     Cust_Name = "Shashi"
                     
                 };
            return userdtl;
        }
    }

Here in LoadUserData() I have set value statically you can set value here from database also As-

public UserInfoBO LoadUserData(string userName)
{
MVCTestDBContext _db = new MVCTestDBContext();
var userdtl = _db.Login.Where(s => s.Email.Contains(userName)).Select(s =>
new UserInfoBO()
    {
       Id = s.Id,
       Email = s.Email,
       UserType = s.UserType,
       Cust_Name = s.CustName,
                     
     });
return userdtl.FirstOrDefault();
}

 

Now set above Class data in session –

Go to Home Controller Index Method and write below code –

public IActionResult Index()
{
    UserInfoBO userInfo = uf.LoadUserData();
    if(userInfo!=null)
    {
        HttpContext.Session.SetString("UserInfo", JsonConvert.SerializeObject(userInfo));
     }
  return View();
}

 

Add another Controller And write below code to get session data

public IActionResult Index()
{
    var uf = HttpContext.Session.GetString("UserInfo");
    if (uf != null)
    {
        var userInfo = JsonConvert.DeserializeObject<UserInfoBO>(HttpContext.Session.GetString("UserInfo"));
                ViewBag.usertype = userInfo.UserType;

     }
Return View();
}